Extension device



' Dec. l0, 1929. E, G. CARL ON 1,738,561..

EXTENS ION DEVICE Filed June 15. 1928 IN VEN TOR.

. ATTORNEYS.

Patented Dec 10, 1929 EDWIN G. GARLSON, or nIvEnsIDII, nnom: ISLAND,ASSIGNOR T PE DEL CHAIN 00., on rnovrnnnon, anozon ISLAND, A FIRMcomrosnn or FREDERIC SIEIDEL AND EUGEN SPEIDEL EXTENSION DEVICEApplication filed June 15, 1928, Serial No. 285,750.

vice for use more particularly with a wrist Watch strap; and has for itsobject to provide a plurality of hingedly connected sections which maybe unfolded to extend the efiective' length of the strap with stud andrecess means between two of the sections to hold them in foldedposition. 7 A further object of the invention is the provision of anopening in one of the sections with a stud on another of thesections toextend through the opening and frictionally engage an edge thereof witheach of the engaging parts tendingpto move the part engaged in alongitudinal direction to retain the sections in folded position. I

This invention further consists in the provision of a resilientlysliding part in one of the sections to which one end of the strap isconnected, whereby elastic action is provided either when the device isin folded or contracted position on the wrist or when the device isunfolded to permit a still further extension of the strap to be passedover the hand in removing the strap and its wrist Watch from the wrist.

With these and other objects in view, the invention consists of certainnovel features of construction, as will be more fully described, andparticularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a top plan view of the extension device in contracted orfolded position showing the parts of the wrist watch strap attachedthereto. 7

Figure 2 is a top plan view of the sections of the device in unfoldedposition with portions broken away to show the construction bywhich anelastic action is obtained.

Figure 3 is a side view in central section ofthe device extended asillustrated in Figure 2. V

Figure 4 is a sectional side view of two of the sections with the spuron one of the sections extending through the opening in another vof thesections.

Figure 5 is a perspective view of the sliding partattaehed to one endofthe strap.

Figure 6 is a section on line 6-6 of Fig-' ure 2.

F igure7 is a section on line 7-7 of Figure 2 showing the hinge mountingof one plate section in theside walls of the channel section. p

Figure 8 is a section on line 8 -8 of Figure 2 showing the resilient pinforconnecting one end of the strap to the end of thesection'.

Figure 9 is a section on line 99 of Figure 2 through the spur.

Figure 10 is a side elevation of the device in folded position.

7 Inthe use of unfoldable devices for temporarily extending the lengthof a wrist watch strap for removing the strap and watch from the-wristby passing thesame overthe hand of the wearer, it isoften desir able toprovide some elasticity of the strap so as not to bind the wrist as itis enlarged due to the use of the muscles of-the hand and arm, which Ihave accomplished by slidably mounting a part to which the strap isconnected in one of the sections with yielding means between the partand the section tending to house the part and movethe strap tocontracted position, and in this construction I have provided a stud onone of the sections so formed as to require a longitudinal resilofthestrap parts, each of. which is provided with a suitable end member 12for connection to a wrist watch. The opposite ends of the strap partsare connected to an extension de-' vice 13 which may be unfolded asillustrated inFigure 2, to temporarily extend the effective length ofthe strap for passing the strap reference to the drawings, 10 desigwitha watch attached over the hand of the wearer without separation of anyof the parts.

This extension device has a body section 14 generally channelshape incross section with a top wall 15 and side walls 16 between which at oneend thereof a cross bar 17 extends. A U-shaped slide 18 is mounted withits arms on each side of the cross bar 17 with a spring 1 19actingbetween the bridge portion 20 there of and the bar 17 to move theslide into housed or contracted position, as illustrated; in F ig; ure3. The end of the strap part 11 is suitably fastened between the freeends 21 and 22.

15 of the arms of the U slide by means of fingers 23' binding'the endsthereto:

The two plate sections 24 and 27are hinged together and hinged to thechannel' s'e'ction. The intermediate plate section 24 has-outm wardlyextending trunnion portions 25'pivot:

ally mounted in the openings 26 in the chan nel walls while a pin andeye oint-28 pivotal- 7 1y connectsth'e two plate sections togetherwhereby both plates may b'e'swung and fold;

ed one against the other and be swung] to be partially housed in thechannel sec'tion14, Sections 14, 24mm 27 are-held in folded position bymeans of a stud of spur 29' on section'27 extending through an opening30. 'in'section 24 and frictionally engaging'fihe marginal end and edgeof the. opening which is'remo'te from the hinge connection of thesections 24 and 27 The spur is formed from the sheet stock of thesection and lies in a "plane generally longitudinahofthe section asdistinguished from a transverse direction so that its greatestresistance to bending is in this-plane. The spur 29 is formed by cuttingspaced portions of the section 27 and folding together the two parts 31and 32 each having an'overhanging'portion 33 on its edge distal orremote from the hinge connection forming an undercut portlon 34 intowhich the marginal edge 35 of'the opening 30'ex-I o tends to hold thesections in close engagement by a longitudinal" resilient action, Thisspur 29' alsoserves' as a guide forthe side edges of theopening 30 toalign the se'ctions 24.

and 27in foldedposition- 27 imq which the resiliently mounted portions38*of a. pinj'37 extend to detach'ably' connectthe' tip 39 of the strappart 10. The.

i finished appearance'tofthedevice when in folded position; r

A fingerpiece 421 is1f srm ed by extending the topwallleoffthe channelsection 14.be-' ne'ath which the thumbnail or finger may-be inserted toinitially swing the sections one Ears 36 are formed'adjacent the endsection upon the other in moving the same to unfolded position.

By the formation of the spur with its maximum dimensions extending in alongitudinal direction with reference to the device,

as illustrated in the drawings, and causingits edge to do the holdingand receiving the friction for snapping the parts to and from closedposition, the maximum strength of such fastening is providedwhichwillwithing or straightening out of the sections towar'd'ia singleplaneto assist in'the' snapping" together of the-parts by the spur 29 extendv ing'thr'u -the openin -'30. I

By the provision of an elastic or yielding action between the strap andthe extension the same may be-worn with greater comfort on the wrist ofthe wearer and yet an added extension may be securedjwheredesired forpositlon'ing the same over an unusually large hand, I p I The foregoingdescription is-directed solely towards the construction illustrated, butI desire ittobe understood that I reserve the privilege of resortingtoall the'mechanical changes to which the device is susceptible,

theinvention b'eing' defined and limited only by the terms of the,appended claims;

I claim: a

V 1. In a-w'ri st watch strap, an extension do vicecomprlsing apluralityof sections hinged together to'be'folded one-on another, one" of saidsections having an opening therethrou'gh, a spur on a second sectionpositioned to extend through said opening, said spur having its greatestresistance tobending ly-' ing onfa plane extending generally'longitudinallv of the device with its edge distal from the hinge connectionhaving an overhanging portion to extend over the edge of said openingremotefro'rn the hinge cor' nection toiho'ld thesection's together,there being sufficient resiliency of the'parts longitudinally of'the dcvice toipermit said spur to be frictionally withdrawn from said opening,and a thirdsection havingdepending' sides within which said othersectionsn'est-f when in folded position.-

2. Inea-jwrist watch strap, an extension d e-c 'vieecomprisingarplurality of shee'tmetal sect-ions hinged together to be foldedzone onanother, one of said sections having an openlng therethrough,-sa spur ona second section posltioned t o'extend through sa1dopen1ng,

said spur being struckup from the sheet stock and lying in a planegenerally longitudinally of the section and presenting its edge forcooperating with the edge of said opening remote from the hingeconnection to hold the sections together and aligned in folded position,and a third section having depending sides within which said othersections nest when in folded position.

3. In a wrist Watch strap, an extension device comprising a plurality ofsections hinged together, one of said sections having an openin gtherethrough, a spur on a second section positioned to extend throughsaid opening,

. said spur comprising two separate sheet metal parts struck uptransversely from the section on which they are positioned and meetingat their opening entering end and having their edges overhanging in adirection longitudinally of the device to engage the edge of the openingremote from the hinge connection whereby a longitudinal resiliency isrequired to snap the parts to and from engagement, and a third sectionhaving depending sides within which said other sections nest when infolded position.

4. In a wrist watch strap, an extension device comprising a pluralityofsections hinged together, one of said sections having side earsbetween which one end of the strap is secured, another of said sectionsbeing channel shape with side walls, the edges of saidears and the endedges of said side walls being shaped to fit together, and means formoving and holding said edges in abutting relation whereby there is nogap between them. 7

5. In a wrist watch strap, an extension device comprising a plurality ofsections hingedly connected together to unfold to temporarily lengthenthe strap, one of said sections being channel shaped in cross section, across bar extending between the walls of said channel section adjacentone end thereof, a U shaped slide mounted in said channel section aboutsaid bar, a spring acting between said bar and the bridge portion of theU-slide, one of the arms of the U-slide having fingers to extend overthe other arm for securing one end of the strap between the arms of saidslide, and means for attaching the free end of another of said sectionsto another end of the strap.

In testimony whereof I aflix my signature.

EDWIN G. CARLSON.

